Found them! The reference is RG13, piece 43, folio 125, page 20.
The question is, where does Mary fit in as Thomas's daughter? There are more than one Mary Dwyer born in Kensington/Chelsea around that time (abt. 1871). Perhaps ordering her marriage certificate to William Hickey is a good idea, just to make sure she is his daughter.
Found a possible entry in the 1881 for Mary Dwyer, daughter of Thomas:
2 Portland Place, Pottery Lane, Kensington (RG11, piece 31, folio 32, page 3)
Thomas Dwyer, Head, mar, 50, Labourer, born Limerick, Ireland
Ellen Dwyer, wife, mar, 44, Born Ireland Cork
Mary F. Dwyer, dau, 10, born Kensington.
I don't know what you makes of this?
Is it 'the other' Thomas Dwyer I wonder?
Ninakin